GMAT Strategy

Here is my story so far:

1. Prepped for the GMAT for 3 months - systematic, good strategy, studied 5-6 days a week.

2. Made flash cards, reviewed then twice a week, made an Error log and logged all the incorrect questions from OG and revisited them twice before the test.

3. Always reviewed both the correct and the wrong answers and spend atleast 2 hrs after practice tests reviewing.

4. Took 11 practice tests. score ranged from 560 to 700

5. Took the GMAT last week end and score 640 (Q44, V34)

Needless to say I'm unhappy with the outcome and am planning to retake it next month say mid-june. So i have about 7 weeks. And this time I desire to score more than 680 (The schools that i'm targetting have their avg score from 680 to 700)

Right now i'm trying hard to come up with a plan, a strategy to prepare more efficiently. I think my weakness are Word problem in which i tend to spend too much time, Number properties (careless mistakes), SC (the tough ones). My all i could come up with was Strenghtening my basics.

I bought the MGMAT number properties and word translation book, and also the Kaplan Verbal workbook. And plan to study for 2 weeks to strenghten my concepts and then redo all the OG11 problem which i have already gone through twice. Then take the 2 GMATPrep tests (again, i've already taken them each twice).

Can anybody comment on my approach for the retake? Am i doing it right or am i wasting time? Do you guys have a better idea/strategy.

Thanks in advance for you Invaluable advices and suggestions..

HK